tv Charlie Rose PBS September 1, 2010 12:00pm-1:00pm EDT
rose special edition. in the seventh episode of our brain series we look at the emotional brain. >> we are talking, as you outlined so well, about emotions. these subjective experiences, states of preparedness, n response to specific people, the situation is we are gathered together with great anticipation of pleasure for this round table that we're going to have tonight. and emotions are designed to enhance our capability for pleasure and to decrease our exposure to pain. >> rose: the seventh episode of the charlie rose brain series underwritten by the simons foundation coming up.
>> rose: tonight we continue our exploration of the most complex object in the known universe, the human brain. this evening, the first of two conversations on the science of emotion. everyone is familiar with such feelings as joy, anger, excitement, and envy, but science is just beginning to understand where these emotions come from and how they control our behavior. this evening we will focus on how the brain regulates pleasure and reward. the pleasure and reward system involves several different brain regions that communicate using chemical signals called neurotransmitters. the this circuit helps us to repeat the behaviors that make us happy while avoiding those that make us miserable. but as any adult knows, pleasure is not always good for you. tonight we'll also explore particularly dangerous forms of pleasure-seeking, addiction. long considered to be a moral weakness, addiction is now understood to be a biological disease. finally, we will explore the role that emotions play in decision-making and social
interaction. next month, in part two of the emotional brain, we will turn our focus to negative emotions such as fear and anxiety. joining us tonight, a group of scientists who have devoted their lives to understanding the emotional brain. daniel salzman, he studies how the brain assigns an emotional value to the information that it receives from the five senses. he is an assistant professor of sky tri and neuroscience at columbia university. wolfram schultz. he studies how the brain's reward systems affect decision-making and learning. he is a professor of neuroscience at cambridge university and a fellow of the royal society. nora volkow. her research into addiction helps us understand drug abuse as a disease wrather than a moral weakness. she is a director of the national institute of drug abuse in washington, d.c. eric nestler, through research on mice, his work his illuminated the molecular basis
of drug addiction. he is chair of the department of neuroscience and director of the brain institute at mount sinai medical center here in new york. and once again, my co-host is dr. eric kandel. he is a nobel laureate, as you know by now. also a professor at columbia university and a howard hughes medical investigator and, as you also know, a great friend of this series and the man who has helped us once this miraculous organ. welcome. >> pleasure to be here as always. >> so as we go through this, as we have been gone from understanding visual perception and understanding the developing brain and the aging brain and now we come to emotion. tell me what we mean and how does the brain connect to emotion? >> well, as always, you outlined it extremely well. emotions are a family of subjective experiences, states of readiness that we all
experience in response to significant people and situations in our lives and emotions are designed to enhance our opportunity for happiness and decrease our exposure to misery. it turns out that the first person to really consider the biology of emotion sr., in fact, our friend charles darwin, the greatest biologist of all time. in the course of his classic work on evolution he realized that emotion is an extremely important subjective state that is universal. it's shared by people in all cultures and it's shared by all animals. and this made him focus on the fact that emotions are part of a basic approach avoidance system that is designed, as you indicated, to enhance our opportunity for feeling good and decrease our opportunity for
feeling miserable. >> rose: and here is the book, charles darwin "the expression of the emotions in man and animal" published in 1872. >> a remarkable book. and in this book he points out that in addition to emotions being of personal value that enriches our mental life, emotions als have@ a social function. they convey emotion from one foreign another. for example, they're important in mate selection. more over, darwin pointed out that the social aspect of emotion communicated through facial expression. this book came out in the 1872 two years earlier a modification in printing occured that allowed you to reproduce photographs inexpensivefully print. and this book is one of the first books that is literally filled with photographs of various kinds of people and various emotional states. and darwin is particularly
interested in children. he studied his own children very carefully, was curious about their behavior and it struck him that children expression emotions in a particularly pure and powerful form and here we see approach happiness and sadness in achild. and this, of course, raises the question how do we classify emotion? and darwin implied and we now have ner good reason to believe that we claskifiedthem along two dimensions: valence and intensity. here we have valence. so there are anywhere from six to seven emotions, i illustrate seven here, that range from happiness that is approach, surprise, disgust, contempt, anger, fear, and sadness. moreover, for each of these, there are degrees of intensity. so you can be happy very slightly or you can be deliriously happy. this is true for each of the emotions. and, of course, this raises the question what is the anatomy of
the emotional system. as you indicated, today we're considerg positive emotion and there are four structures that are important here. the amygdala, which orchestrate emotion, the try yay tum which gets recruited for habit striatum. now, there is cognitive control of emotion whether it's appropriate to exercise a particular emotional response in this context versus another that is mediate bid a higher level structure called the prefrontal cortex that interacts and in part controls the other important structures, the amygdala and striatum. all of them are run by the dope dope ma energy i can system in the brain. one of about this sys,em and particular the dopamine pathway involved in positive smogs that it is involved in a number of disease states. so it's disturbed in
schizophrenia, it's disturbed in parkinson's disease and it's also co-opted, as you indicated, in addictive disorders. so cocaine and heroine hijack this system. and one of the great insights we have is exactly how this occurs. these drugs simulate the activation of the this system. they take it over. >> ros are there stages of addiction? >> there are several well-defin stages of addiction to begin with, there's the addictive process itself whereby as you outlined people begin to experience an addictive drug, get the pleasure of addiction as their system hijack it is dope energy i can system and that@ focus on addiction so consumes their live they focus on getting the drug and enjoying the drug to the exclusion of all other aspects of their lives.
they neglect their families and their jobs and their health knowing that they're destroying themselves they continue to use the drug. number one. number two, as they continue to use it the dosage necessary to give them the high increases. they become tolerant. so the dosage they use is no longer effective. they need go to aigher usage. and nora volkow demonstrate house the striatum which gets recruited by something like cocaine no no longer responds once the person has used for cocaine... cocaine for some time. one of the most tragic aspects of addiction is the third phase, there's always the possibility of relapse. so even after a person gives up the use of drugs for weeks, for months, even for years, exposuretor the sight of the drug, the smell of the drug, walking the street in which they used to buy the drug but bumping
into people that use the drug brings a tremendous urge to use the drug back to them. as a result of this, very, very easy for people to relapse and to start using these drugs again. this is why we realize that addiction is a life long disease it can never be cured. people can be helped with it but they have to be monitored throughout their whole life. and you would think a process like this is extremely difficult to study. the fact is, we've made quite good progress in understanding it through two quite different avenues. first of all, we can study it in people using imaging techniques and nora volkow has pioneered this. we could also study it in experimental animals, we can study in the monkeys as daniel salzman has done. we can study it in rats and mice as eric nestler has done and we can even study it in flies as a number of people have done.
so there's a number of experimental approaches to study addiction and we're getting insight into how it works. >> rose: why are we dividing emotion into two parts? it's a nice neat division between pleasure and reward and fear and anxiety but why this... >> it's a nice subject and there are different diseases associated with positive and negative emotion. we spoke about the positive emotion. addiction is the prototip i can example that co-opt it is positive emotion. we now have a large number of veterans coming back from iraq that suffer from excessive negative emotion a memory of being wounded themselves, having shells explode around them. these people come back with a disorder called post-traumatic stress disorder which is a remembrance of a frightening episode so the fear stays with them for a long period of time.
and the next program we're going to discuss in detail negative emotions, the role of the amygdala in both of these emotions, negative as well as positive, the cortical control systems from this and the fact that we can now begin to treat post-traumatic stress disorder in a remarkably effective way and we're going to discuss the treatment of this disorder. >> rose: all right, here is our first of two hours on emotion which we look at pleasure and reward with our panel. tell me about emotions and some sense of the variety of emotions. >> so this is the challenge for neuroscientists in general. when you move on to mental processes to study mental processs that can vary enormously in many dimensions and emotion is example of that because we have a very rich language for being able to describe different types of emotion. the question then becomes for neuroscientists is how do you take different emotions such as disgust, anger, joy, happiness and how do you map them into brain circuits when you don't understand how those brain
circuits snungs that's the starting point. all of us are psychologists to some extent at the beginning in order to be able to understand how to map these linguistic terms into processes that might actually with b represents in the brain. and there there's at least two components of emotion that are critical for understanding in that regard and someone that everyone knows what an emotional experience is like but if you think about it far minute has a conscious component and an unconscious component. if you think about what that, what does it mean? it means there are certain aspects of our emotional responses that are happening without us even thinking about it and there have been to be brain systems, then, operating below the level of our consciousness that would execute those processes. at the same time, we have conscious feelings of emotion and awareness of those emotions and we have to come up with ways of understanding how the brain could be modulating emotion a way that would influence our conscious awareness of them. so that's one aspect of trying to understand emotions to be able to understand the divide
between conscious and unconscious processing in the brain. >> that's a very interesting example because maybe you can give us a specific example of that. if you have a lion all of a sudden coming into this room, we would be prepared to run away before we specifically perceived that it's a lion. so we have a physical response to it knowing we're in a dangerous situation before we perceive what the specific nature of the threat is. >> rose: >> it's not just that we want to flea, but there's a whole range of other bodily responses. we'll start sweating a little bit. so there's aspects of the response mediated by our nervous system that are automatic happening below the level of consciousness and they are part of our emotional experience. and for decades scientists have debated in a chicken and egg fashion, which comes first, those physiological responses in response to stimuli or the consciousness... conscious awareness of those physiological responses. so this conscious/unconscious divide is a big issue in terms of defining emotions but there's
another aspect that eric touched on earlier which is that despite our very rich language for describing emotions, you can actually map many aspects of these emotions on to two axes. one has to do with how good or bad something is, the valence of the emotion. the other has to do with the intensity, right? so you can get really excited when you're in a fearful state and really excited when you're in a happy state, right? so the valence there is different but the intensity is similar. so you have these two axes which you can map most emotions on to those two axes in some way. i'm not saying it captures the entire essence of that particular emotion, but you can reduce the emotional experience to those twoing a sneeze a very useful way in terms of looking at brain systems. >> maybe you can take us through the anatomy of the emotional system. >> right. so we were talking about different aspects of emotion that need to be coordinated in the brain and the first slide is giving you a window on some of these key structures. this is a literal view of the human brain so you're... your
cover of the brain is the cerebral cortex and you've talked about the pip poe campus, a structure buried in the medial temporal lobe and involved in learning and memory. and eric had mentioned earlier in the introduction to the show that the key coordinator of the emotion is the amygdala which sits just anterior to the hippocampus. and the amygdala is a key coordinator of emotion because it sends projections both to subcortical structures, subcortical structures that modulate the different physiological responses we are discussing such as heart rate and how sweaty you are when you're nervous that are part of the automatic or unconscious aspect of emotional experience and the amygdala also sends projections up to the cerebral cortex including a prominent projection into the pre-frontal cortex which may well mediate how emotion can influence different aspects of cognition. some of the other structures that have been mentioned already were dopamine neurons as well as
the striatum, another target of dopamine neurons and we'll be discussing all four of those structures throughout the show. now, emotion, of course, needs to be regulated and in the regulation of emotion, that's thought to happen in part by communication that comes from the pre-frontal cortex back down to the amygdala as shown here. so these are the structures that we're going to be talking about and dopamine actually broadcasts its signal broadly throughout the cerebral cortex. so you can here dopamine neurons which have prom innocent projections up to the pre-frontal cortex and projects nicely to the amygdala as well. so it's in a position to broadcast some kind of information, in particular we'll focus on the information related to rewards and reward prediction today to wide parts of the... wide aspects of the brain. >>. >> rose: how do rewards come into this? >> well, i think rewards are basic components that will lead in one way or another to
emotions. so the standard view, of course, is rewards make you happy. but in neuroscience we have a little bit wider view. we need to cast our net a bit wider. so we think rewards are all objects that make us approach behavior. that means that we want, that we want to spend energy on. rewards make us learn things. then how did rewards enter neurobiology? it's obviously a very general concept and even if you try to scale it down a little bit with these examples in the 1950s, olson millner did a very famous experiment, a series of experiments in which they put small wires into the brains of little rats and rats would push a lever to produce a dournt their brain. the current is so weak you wouldn't sense it even as a tickle on your skin. and the rats would press a lever over and over and over again to
just have that electrical stimulus inside their brain. not just anywhere, it was in particular parts of the brain where you have to do that. and then the rats... it was so strong the kind of approach behavior and the behavior generating power of the stimulus they would stop eating, they would stop drinking, they would stop having sex. they would basically die. actually, they would die if you would let them go on and stimulate. they wouldn't eat. >> rose: so the pleasure was so great they would sacrifice everything. >> more pleasurable than anything else. a remarkable set of experiments. >> amazing. absolutely amazing. that's it. >> just as an aside, peter millner who together with olds is the husband of brenda miller. >> rose: i was going to... yes, green was here last time. >> it may go beyond pleasure, though, in that it's not just pleasure. there's something about this stimulus that prompt i don't say tow repeat it again. >> rose: what would that will be though?
>> i think that's a question that you'll... >> i think this is what we call the reward predicting stimulus. so we'll get to that in a minute. then the question was... i mean, what brain systems are these? that you stimulate? you could, of course, look at your electrode and see where it is and it's in the brain stem where it is quite... in the anterior midbrain where it's quite complicated to finding individual brain structures. and then came the revolution in neurotransmission, in chemical neurotransmitters in the '50s, '60s, '70s. a number of neurotransmitters were identified including one called dopamine. so dopamine is a chemical that is a neurotransmitter located in neurons, released from neurons that have identified anatomic positions in the brain sfochlt so the dopamine neurons project to the striatum, the pre-frontal cortex and the amygdala and a few others. these the most important ones. and then the manipulation of the
dopamine neurotransmission by giving dopamine antagonists and other substances would modify reward-seeking behavior and in particular it was found out by people like roy wise and associates and other people that these electrical stimulation for brain reward was partly related to the dopamine neurons. in fact, stimulating the dopamine neurons meant that the animal would repeat the electrical stimulation. it's like getting award. >> rose: tell us about addiction. >> at the essence of addiction is why do people take drugs and they take drugs because they want to feel good and drugs make you feel good and they make you feel good, as eric was mentioning, because they hijack these reward systems. all of the drug abuse that we know, that can make people... that increase dopamine in the pleasure centers of the brain and this is believed to actually be crucial for producing the rewarding effects and to ultimately lead to the changes
that result in addiction. now, with imaging technologies, we can actually now go inside the brain of a people that... of a person addicted to drugs and see what areas of the brain may be disrupted that could explain why is it a person addicted to drugs can not control the urge to take the drug even though they actually can tell you sometimes they are no longer even pleasurable anymore. they were pleasurable initially but as they repeat the taking of the drugs that pleasure becomes less and less and they start to take it not to get high but just to feel normal. so with imaging, for example, we can now look inside the human brain and see there off diagram that shows the dopamine cells, normally you cannot look at them you require an imaging technology that relies on radioactivity. and the way you're going to be looking at how drugs increase dopamine is the following way. normally you have dopamine cells releases dopamine when you take
a drug, for example, and dopamine sends these messages by binding to the receptor. you take a radioactive compound that actually binds exactly to the same receptors as dopamine but can only bind when the receptors are not occupied by dopamine. so that allows you to taken a image, then you bring the subject back and you test them when they are taking a drug like cocaine. cocaine interferes with dopamine removal from the space and those t dopamine occupies all of the receptors in such a way that when you give the radioactive compounds the receptives are occupied and your radioactivity can no longer bind and you see the decreasing drug activity which is really a function of the fact that the drugs are increasing dopamine. so you can now use exactly these technologies to go inside the brain of a person that's addicted and a person that's not addicted and to compare the brains when you give them a drug. and it's what you see there. for example, to the left it's a placebo, a saline solution and
you see a lot of radioactivity in the center which is striatum which is one of the main rewards... where one of the main reward areas of the brain is. and then you see the drug and you see the decreasing radioactivity because dopamine went down. so to the surprise of everybody, including us, when we gave it to people that are addicted we saw almost no signal. and this is... because to say that the drug is not so effective in increasing dopamine and we take drugs to feel good and that relates to increasing dopamine then why what is the logic? and what we found actually was very intriguing and very telling but very malignant when we studied the process of addiction. it's something that wolf ham described many years ago which is something that a certain stimulant increases reward it stops producing dopamine with that stimulant and increases dopamine when there's a stimulant associated with it that predicts you're going to
get reward. that's what we call conditioning and that's what pavlov described with his dogs. the sound predicted the animals were going to get fell. well, the same thing is happening in addiction. the people addicted to drugs are increasing dopamine when they see the needle, when they see the person that they had drugs before, in the neighborhood where they actually have been. so look at the images in the next slide which actually show in the left people looking at the video, this is a nature scene and to the right these are cocaine abusers, the same cocaine abusers but now they are not looking to nature they are looking to a video that shows people taking cocaine. you see the radioactivity has gone down because dopamine goes up. so you see that is increasing dope mean the striatum and this is subjectively associated by this individual with a tremendous desire to take the drug. and you can then start to understand why it's so very difficult to a person that is
trying to stop drugs to go back to their environment because everything reminds them of the drugs. everything is condition. so this is an automatic behavior that's going to result in the wanting of more drug. >> it came up a few years ago when billboards were around showing a white... lines of white powder and a ray or blade and the way to get people to stop doing cocaine and we found that that stimulus provided an incredibly strong cue to remind people of these positive memories. >> rose: when they saw that visual image... >> it induced cravings. >> rose: it induced craving when they saw that symbol? >> very interesting study that was in, i guess, about ten or 15 years ago with veterans from vietnam who had gotten hooked on very effective heroin. very high quality heroin. and the amazing thing was they got addicted in vietnam but they could give up the addiction when
they dime the united states because the clues that they had that encouraged them to use the drug were gone. >> rose: no longer a part of their life. >> here the averaged a detective walks out and sees this is the guy that sold it to me, this is the drugstore nearby where it met him and he's reminded of the things that trigger this response. so obviously we're learning a lot about imaging. can we learn anything from animal models about this? >> yes, absolutely. most advances in modern medicine have come about through the use of animal models where aspects of a human disease are recreated in a laboratory animal like a rat or mouse. a major obstacle in psychiatry has been the unique difficulty in generating animal models since so many psychiatric symptoms are inaccessible in animals. hallucinations, guilt, suicidality... >> rose: you can't find them. >> absolutely. and in this context addiction has particular promise because it's far easier to model in an animal than other psychiatric
conditions. so under the right circumstances a rat or mouse will choose to self-administer an addicted... and addict itself to the same range of drugs that people self-administer and addict themselves to. >> this is very interesting because this is also true for fearful conditions. anxiety states can also be modeled and this is what darwin said. these emotions are conserved and so one can study these emotional disorders very effectively in animals. >> absolutely. and the self-administration behavior in animals, like the in humans, is determined roughly half by an individual's genetic nstitution and half by environment. so we know, for example, that chronic stress will increase an animal's vulnerability to self-administer a drug of abuse just as we see in humans. and going back to a point that was made earlier, if a subset of animals is given unlimited access to a very potent drug
like cocaine and heroin, they'll actually overdose and kill themselves. >> rose: where is conscious control in all this? >> well, i think this is a complex interplay between conscious and subconscious processes, as dan had mentioned. it initially starts with a conscious decision to obtain drugs. for the rat it means pressing a lever. but what we've been talking about is that drug stimulus activate it is subcortical signals like that dopamine containing nerve cells that over time can take over. >> tell me about cognition and emotion. >> i think they're asking because cognition has been traditionally situated in the pre-frontal cortex. but we've also come to realize that drugs rose that portion of the pre-frontal cortex and that with repeated drug use actually frontal cortex loses its ability to cognitively control your
desires and emotion. each one of us on any one given day has to make decisions of whether we do something we want to do or we restrain. i want that very much but i'm not going to do it because... i want that chocolate but i don't want it because i don't want to gain weight. sometimes i can control and sometimes i cannot. most of the times i can. in people that are addicted chronically to drugs, that control becomes very difficult. and it's almost for them like... i like to sort of use the metaphor of the brakes of the brain, the ones that are exerting cognitive control. the person that is addicted to drugs does not want to take a drug, it costs them their job, they may end up in prison, their spouse, yet they cannot stop. so it's like a drug, you want to stop but if you don't brakes you won't be able to do it. and that's the pre-frontal cortex. >> rose: the producer showed... peter showed me a passage from john cheever talking about drinking and he looked at his
notes and he knew that drinking was not good for him and how many times had he said "i've got to stop, i've got to stop." and yet he said the next day at lunchtime i find myself taking a baht of of whiskey out. >> it's a powerful habit. >> that's right. it's some of the same neurocircuitry we've been talking about but it becomes hijacked and mediate it is formation of habits that are very maladaptive. so this is now meant to represent in part some of the key structures in their connections in relation to habit formation. so as wolfram has described earlier, dopamine neurons are providing information about reward and in particular about when a reward or stimulus is better than expected. and when you think about a good habit that is adaptive, we all want to form habits when we form habits because they help us survive and we can perform behaviors automatically without thinking about it and it's more efficient. so that can be driven in part by the output for a dopamine neuron
because something happens that's better than expected you want to repeat that behavior. so it's dopamine input structures like the striatum and pre-frontal cortex that mediate the normal formation of adaptive habits. at the same time when these become hijacked during drug seeking behaviors what happens is a particular cue can illicit drug craving which will illicit drug seeking behavior. this is mediate bid dopamine neurons but the convergence of dopamine input and input from the the amygdala into the striatum. >> rose: is so is there where we talk about free will? >> one of your specialties. >> well, it's come up already in the discussion that drug addiction kind of takes you over. so, of course, i mean you give up a part of your free will and you become addicted. whether that's conscious decision or whether that happens. >> rose: you've lost your free will.
>> you've lost a good part... well, a certain part of your free will. but before we get to that stage of addiction, i can't live without having that water. actually not not that one but some water every so many hours. so rewards have a powerful effect of attracting your behavior and this is already a constraint on your free will. the simple fact that we need lick fwhidz the environment that we need to reproduce makes us lose part of our free will. we still have the choice between different alternatives but we're going in one direction. that's towards getting the reward and avoiding negative consequences, that's very clear. the other thing we found is that the dopamine not only signals the reward or signals the reward whatever it's better than what you have received before, it also signals the risk. so risk influences your free will, behavior. and the other thing that risk does is you have a problem
understanding the world. if the risk... if the world is risky it could either be because you don't know it enough or because there is inherent risk, like the weather forecast. we think the weather is basically random but we understand now that better meteorology makes us predict the weather better. so we have reduced the risk by knowledge. by experience, by science. so if you don't that, if you don't have the science, we are getting supertishs. we say well, if i go three times around that tree it will not rain tomorrow and i can bring in my harvest. and things like this. the more we know about the world, the better we understand risk and i think the less we will get superstitious about how certain things will happen. and so this is something where we would say education and the science is actually there to reduce superstitiouss and name us behave in a more rational manner. >> the question of free will is a difficult one, though.
because i think we all believe that individuals must be responsible for their decisions. >> rose: that's where i was going. >> and the bottom line is that drug addicts make bad decisions. the difficulty comes in with the fact that the drugs are targeting the very parts of the brain that control our ability to make those decisions. and so we have to balance. i think nora would agree. we have to balance between looking at an add diktd from the concept of free will, responsibility, yet they do have a drug-induced disease in their brain. >> rose: these... >> these are not bad people, these are sick people. people are addicts. can we do anything about this? are there any treatment approaches? >> absolutely. one of the vital challenges of today is to translate the increasing knowledge we've gained of brain reward circuits, the reasons of the brain gets damaged and an increasing understanding of the way that drugs change the brain at a molecular level into better
treatment. the best treatments today are behavioral. things like 12-step programs like alcoholics anonymous. but recidivism is high. a large majority of addicts return to using drugs even after a few months of completing the best available program. our view is that the goal of medication treatments would be to help counteract these powerful biological forces that drive an addiction and thereby make rehabilitation and psycho social efforts that much more effective. >> rose: >> would you say the behavioral treatments are changing the brain? >> yes. >> rose: the 12-step program the in fact, changing the brain? >> yes, even though we think about behavioral therapies and medication as very different, they both work through biological processes. in other words, they would poet produce positive changes in the brain. >> rose: the end there's a biological behavior at both ends... consequence. >> you're training the pre-frontal cortex to be able to regulate these habits, basically. >> and i want... the point that
i do want to make when we speak of addiction is that it's a chronic disease. so when we're dealing with treatments we need consider it as a chronic model of disease and i want to emphasize because it's very frustrating for me when we're trying to get insurances to pay for treatments of substance abuse and they say "treatment does not work." and it does not work because 70% of patients relapse. well, they relance because you discontinue treatment. we have ( cheers and applause ) >> drew: all right, welcome back the magical thinking that we're going to cure addiction. currently we do not cure addiction. we treat it, like so many other chronic diseases,: hypertension, asthma, cancer. and you have to maintain treatment otherwise the patient relapses. so the concept of high relapse rates is part of the concept of the long-lasting changes. brains... drugs affect the brain that's much longer than after yourself taking it. and we have medication for
example in the case of heroin. we have methadone. for the case of nicotine we have several alternatives for us. >> what do they do as a category? whether it's nicotine or whether it's methadone? >> for methadone and nicotine replacement you have drugs that are acting in the same molecular targets in the brain as the drugs themselves but they do in the a different way. temporarily a much lower level of stimulation. >> a heroin addict, for example, would spend most of his or her day trying to get heroin and taking it. then the drug wears off and the process starts all over again. methadone binds to the same receptor that is being activated by heroin only it stays on the receptor far very long period of time so a person's life can gradually get back to normal. >> rose: then off methadone addiction or snot >> you do. but it's not as disruptive. and it allows normal life to begin: >> one of the things that
emerges from this discussion is how discriminate it had addictive person is. for example, drug companies spent practically no effort trying to develop effective drugs against addiction. >> and that's correct. and it's actually as a result of that it has been very difficult, all of the science that eric was telling us about has translated in some very potentially promising targets for medication. but to bring phlegm the laboratory into the clinic is very costly and for most of the diseases that we know about, those costs are carried by the pharmaceutical industry. in the cases of addiction, the pharmaceutical industry has not been very much involved with the treatments for addiction. >> rose: why is that? >> one of them is the stigma that eric was speaking about. another one is the perception that the person that is addicted to drugs is not going to be able to provide for the cost. the economic cost. >> rose: >> they think that most people who are addicted-- which is not true-- are people on the street. but you also have people who are addicted in major executive
positions. >> rose: universities, everywhere else. are we at a point in which most people believe that addiction is a disease? >> yes. >> rose: and it's not similar play weakness of kharker? >> i think nora's been one of the people who's been making this clear to the general public. >> rose: i understand but have you won the battle? >> well, that's where it comes. you're asking me and i say yes. but when ski that to physicians that are the most knowledgeable about this, i ask them and they say "yes, but..." and that is where you have accepted it. they intellectually have accepted it but they have not changed their behavior which is the health care system for the most part has really removed itself from the screening and the treatment of the substance user and the reason that it is the boss is because it is believed to be a behavioral choice. a choice of the individual when they start taking drugs. and that has been used to stigmatize the problem of drug
addiction but it's not fair. because if you look at the numbers in the united states of kids that get exposed to drug, 40% of kids 18 to 19 years of age have been exposed once in their lifetime to marijuana. 75 or more have been exposed to alcohol. and yet some of them will become addicted and others will not. approximately 10%. and that's not something that you choose. that's genetically determined. >> rose: okay. what comes under the umbrella of addiction? drugs. everything from what to heroin. cocaine. alcohol? >> alcohol. >> rose: food? >> there is a lot of interest right now in terms of consider certain compulsive behaviors as addiction, like compulsive eating, compulsive gambling, compulsive sexual behaviors. >> rose: they are addiction in the same way that... do you think that there may be... >> behaviorally... >> rose: gambling? >> it's very similar.
and we actually have been doing studies comparing the brains of people that are addicted with... comparing them with people that are obese to try to understand whether the same striatum dopamine sir scut involved and lo and behold, it shouldn't be surprising but it was surprising to us how similar the changes are in these two conditions. and it's not surprising because drugs are hijacking a circuit in the brain that evolved to ensure that we had behaviors that would allow us to survive. what are those? they are reproduction, they are food. drugs basically take that over. >> one of the great hopes that emerges about this is society is more willing to accept obesity as a disease than it is drug addiction. and getting insight into how to prevent obesity, which is an addictive behavior in a certain level, might give us insight to the development of drugs for other kinds of addictive
diseases. >> before we say that addiction involves the same brain centers for these different forms of addiction like food and drugs and money, we can at least say here already at the completely unaddicted state that the same parts in the brain called the striatum shows response is activated by all kinds of different rewards. like money, beautiful faces as opposed to standard faces, sports cars. >> rose: (laughs) right. >> sports cars as opposed to standard cars. pleasant music as opposed to background music. humorous comic strips and also romantic love. this is the... people see pictures of a partner with whom they have fallen in love within the last half year and that activate it is striatum more compared to seeing a picture of a person that they have gotten to know since half a year. so all these areas, all these different rewards seem to activate the striatum.
now understand that addiction is an exaggerated form of brain response and behavioral response to rewards and you can imagine if this is already the same part on the brain that acted with rewards that the addiction could have certain sin anatomical components. >> this is the hijacking ideas. >> that's the hijacking idea. so it's not no surprise that the food reward and maybe the drug award or something have certain similar components. >> they're also some hopeful things. for example, there's reason to believe that there are stages in drug abuse that certain drugs are more likely to lead to other drugs. smoking, for example, is a powerful first step. and as one discourages people from smoking-- and that's beginning to happen-- it quite likely will have an effect on other addictive processes as well. >> yeah. and eric's wife has been instrumental with her work in looking at the epidemiological studies to actually show that
kids that were engaging in illicit substances have started by taking nicotine so the question was is it because that was the first drug that was available or is it because those kids are going to take illicit substances will take nicotine or is nicotine doing something in your brain-- which is really interesting-- that could make you more vulnerable as you grow into an adult to other substances and addiction and there is evidence from stories in laboratory animals that indeed early exposure to nicotine modify it is function of the dopamine cells, making them less sensitive to reinforcers, to rewards. so nicotine exposure early on can have longer lasting effects, certainly laboratory animals, that will affect the way that you're going to be responding to drugs. >> it's on everybody's mind because of the stuff that's gone on in the last four or five months about tiger woods. the idea of sex addiction. what is the... what do we know
about that? >> the coolidge effect, that a male exposed to female will after a while tire of cop lating with that female but if you show him another female, that same male who appears exhausted but all of a sudden capable of sexual activity. >> rose: why is that? what happened in the brain? there's some habituation, familiarity which is... it's very much like addiction. >> expected reward. increase in value over time. >> but it made me also smile because it's the same thing with food. with food you can actually... they put you a piece of meat, they can tire of it, but then they bring dessert, because you're full, you'll eat dessert. anything that's novel will activate the dopamine system. >> rose: they again. everything gets tired at some point andactivates the dopamine... >> to become tolerant. so a natural stimulant will activate the dopamine cells
because as you become satiated, it becomes less effective. not with drugs... >> rose: how why is drugs different? >> you do not become satiated. >> is it possible that part of the addiction is to risk? >> that's exactly right. and i that i mean's one thing characterizes the behavior of people that take enormous risk and having, say, multiple sexual partners. it's not rust the sexual satisfaction, it's the risk and enjoyment that they get from doing in the dangerous situations, right? and wolfram has spoken about how risk can activate dopamine neurons so this dang kerr maybe even accentuate the sense of pleasure that they get from these types of activities. >> the interesting something that some of these same neurons are also activated by risk. and the over brain structure that we know that responds to risk very well to stimulate and predict the risk is over the frontal cortex. these not the same neurons but
it's the same area. so they're very close by. >> there's another test with experimental animals that show as you become addict there had's anatomical changes in your brain just as you see with learning. so therefore the chance of doing it again are increased and this is probably the case with risk as well. we don't have the data there but as you engage with this and are successful, you're encouraged to try it again and again. >>. >> rose: in every episode we've done we've devoted a portion of it to genes. is it less... there s there less evidence here of the genetic sdmex >> addiction is roughly half genetic which is actually an astounding figure based on how the role of psycho social factors contribute to addiction as well yet it's 50% genetic. that's as heritable as high blood pressure and cholesterol. >> rose: and they can identify the genes? >> no, that's the problem.
that's what nora was mentioned. we are just getting the techniques that will enable us to find the genes. >> for an animal you can do something which is very neat which is modify one gene and that dramatically modifys the vulnerability of that animal to take the drug and compulsively ingest it. so with one gene you can dramatically change the vulnerability of an animal to drugs. just illustrating how important these genes are and, again, this is not surprising. when you go out with your friends and go to dinner and have a glass of wine you can rapidly see how differently we all respond the same drug. and the reason we're responding differently is your biology, your genetics. >> rose: (laughs) yes, it is. indeed, true. let me go to what you do at the national institute of drug abuse. what are you doing there? what's the goal and the support you have from the government? >> well, the institute funds
researchers in order to advance knowledge of drug abuse and addiction such that we can treat the drug addiction in this problem. i always say my simple, simple task is to get people that are very, very bright to be able to get them the resources so that that they can use their brains and actually come up with solutions to the problems. so we focus in two major areas chouchlt knowledge help us prevent? how can knowledge help us treat drug abuse and addiction through science? and that involves, of course, very basic science like work that you're hearing today but also it involves a better understanding of what practices are going to be more effective with which we currently have for which there is knowledge. there is knowledge and yet we're not applying them. so what practices are more likely to prevent and treat people so we can decrease the significant burden of drug abuse in this country. >> rose: let me conclude with this which eric knows that i like to do.
in research, in the study that you do, what is the one question you would like to see answered? >> how can we cure addiction? >> free will. >> rose: free will? >> identifying specific genes that control vulnerability or resistance to addiction. >> learning how the pre-frontal cortex can regulate our emotions. >> i'm interested in learning and memory and addiction is, in fact, a learning process. we've recently begun to explore a molecule that will is involved iner the pec situation of memory storage and it will be interesting to know if it's involved in the perpetuation of addictive process. why people relapse so easily. they can be off drugs for months but they walk out in the street, see a sign, boom, it's like a condition stimulus they go back and get addicted again. i would like to see if this kind
of a molecule is involved in that as well. >> rose: what do you think we'll talk about ten years from now if we convene the same group to talk about the emotion the brain >> smogs an area we knew very little about 20 years ago. we've made remarkable progress so i think this is an area in which the progress would be disproportionately large. we'll have a much better understanding of the reinforcing systems of addiction, we may have initial insights into how to combat addiction and we'll see how obesity and drug addiction relate to each other. many of the themes we outlined here we'll make progress on. having said that i should tell you in biological terms ten years a very short period of time. >> and i think we would also have a better knowledge of conscious versus unconscious emotions. so much of our behavior is controlled by unconscious processes. >> this is what freud saed said. >> rose: thank you all. >> nobody believe this is stuff
and he's right. >> rose: there is our panel weighing in on part one of our two-part look at emotion and the brain. fwoort is... >> negative emotion. we're going to discuss fear and disorders rhetted to fear. we'll talk about post-traumatic stress disorder and there's good news about this disorder. there are a number of effective treatments, both behavioral treatments and psychofarm logical treatments that are extremely effective. >> in so there is a biological basis of post-traumatic stress disorder? >> that's right. that's right. >> rose: thank you for joining us. we look forward to seeing you next time. emotion part two. fear and anxiety. see you then.